1. Field of the Invention
This invention relates generally to magnetic alloy, and more particularly to magnetic alloy for use with a magnetic recording medium in thermo and magneto printing.
2. Description of the Prior Art
There are various methods for printing (or copying) recorded informations from one magnetic recording medium such as a magnetic tape to another magnetic recording medium, possibly also a magnetic tape.
One of these methods is proposed in the U.S. Pat. No. 3,496,304, and the method is as follows.
1. Preparing a master magnetic recording medium (simply saying a master carrier) being recorded with a original signal thereon, an intermediate recording medium (simply an intermediate carrier) and a copy magnetic recording medium (simply a copy carrier) on which the original signal should be copied. PA1 2. Heating the intermediate carrier above its Curie temperature. PA1 3. Placing said heated intermediate carrier in contact with the master carrier during cooling from the heated temperature to a temperature below the Curie temperature of the intermediate carrier. This is thermo printing process. PA1 4. Separating the master carrier from the intermediate carrier. PA1 5. Placing the intermediate carrier in contact with the copy carrier and applying A.C. bias magnetic field. (This is magneto printing process.) PA1 6. Separating the intermediate carrier and the copy carrier each other. The original signal recorded on the master carrier is printed on the intermediate carrier in the thermo printing process. The printed signal on the intermediate carrier is then printed on the copy carrier in the magneto printing process. Finally, the original signal recorded on the master carrier is printed on the copy carrier. In this method, by using an intermediate carrier, an original signal and a printed signal are the same each other in the direction of magnetization. So it is no need to prepare a particular master carrier which is recorded with a mirror image of the original signal, and every normally recorded magnetic recording medium can be used as a master carrier. But in this method, the intermediate carrier has to satisfy hard characteristics in magnetic property, mechanical property, physical and chemical stability, durebility and so on.
In the U.S. Pat. No. 3,496,304, Chromium Dioxide (CrO2) tape is used, because CrO2 has a lower Curie temperature (Tc = 120.degree.C). but CrO2 does not satisfy the required characteristics, especially coercive force and residual magnetic flux density.
Another material suitable for use with an intermediate carrier is iron-cobalt-phosphorus sputtered coating on a non magnetizable support. For example, sputtered coating of (Fe.sub.0.85 Co.sub.0.15)P.sub.0.5 has magnetic characteristics superior than that of CrO2 and proper Curie temperature. But iron-cobalt-phosphorus is not so stable chemically, by heating the same it is assumed that phosphorus atom evaporates from the sputtered coating, and iron-cobalt is oxidized rather easily. Further, manufacturing of such sputtered coating of uniform composition is difficult and has to employ complicated apparatus.